The presence of hydrocarbons in soils has become more problematic in recent years. The hydrocarbons, often inadvertently spilled on the soil, particularly around service stations, airports, and refineries in industrial areas and urban centers, have leached and percolated through the soil to aquifers, reservoirs, lakes and other sources of potable water. In many areas, local, state and/or federal environmental regulations require that the contaminated soil be dug up and removed and stored indefinitely in hazardous waste sites, at substantial expense and inconvenience as well as burdening public contamination holding facilities.
In my prior U.S. Pat. No. 4,748,921, there are disclosed a method and apparatus for removing volatile or flammable hazardous liquid waste from soils utilizing a rotating drum. The contaminated particulate soil is exposed to flame and hot gases of combustion and the volatile hydrocarbons from the soil are burned in the drum during the process. Although that apparatus and method are suitable for treating smaller quantities of particulate soil, especially in smaller batch-type operations, it is not entirely suitable or efficient for substantially larger quantities of soil treatment.